Thread bobbin and method of and device for forming the same



ANDERSON THREAD BOBBIN AND METHOD OF AND f N l w M 8 Y 8 a mu m 8 my R A, v /.m 2 t a W w T w A z w 7 1 m Nov. 22, 1949 J DEVICE FOR FORMING THE SAME Filed Aug.

Patented Nov. 22, 1949 THREAD BOBBIN AND METHOD OF AND DEVICE FOR FORMING THE SAME John Howard Anderson, Glen Rock, N. J assignor to The Linen Thread 00., Inc., New York, N. Y., a corporation of Delaware Application August 5, 1948, Serial No. 42,668

6 Claims.

In certain outsole look-stitch shoe sewing machines, of the type commonly known as the horn type machine, the shuttle is provided with a revolving shell in which the thread bobbin is pressed or driven with the outer periphery thereof engaging the inner side of the cylindrical wall of the shell. The bobbins are pulled or unwound from the inside, and consequently must tightly fit the shells perfectly or else they break down and loosen, causing snarling of the thread in the shuttle case. I-Ieretofore considerable difficulty has been experienced in thus properly fitting the bobbins in the shuttle shells, due to the shells or the bobbins being out-of-round, or the bobbins not being formed of the exact diameter required.

One of the objects of the present invention is to provide a thread bobbin of the character indicated having means for insuring proper fitting of the bobbins in the shuttle shells, irrespective of such defects in the bobbins or shells.

Other objects of the invention are to provide a novel and improved method of and device for use in forming bobbins of this character.

The invention is illustrated by way of example, in the accompanying drawing, in which:

Figure 1 is a view in perspective of the bobbin in its preferred form;

Fig. 2 is a plan view of a bobbin and shuttle shell with the bobbin mounted in the shell, the bobbin and shell being enlarged;

Fig. 3 is a sectional elevation, taken on the lines 3-3 of Fig. 2;

Fig. 4 is a plan view of a portion of a device Which may be employed in forming my improved bobbin;

Fig. 5 is a sectional elevation, taken substantially on the line 5-5 of Fig. '4;

Fig. 6 is a view corresponding to Fig. 1 of a modified form of bobbin; and

Fig. 7 is a similar view of another modified form.

My improved bobbin is of the type comprising an annular mass of thread 2 which is universally or cross-wound, the bobbin when in use being pulled or unwound from the inside. Previously to winding the thread is waxed, and braided thread may be employed. After the mass is thus wound, it is compressed both circumferentially and, axially.

In the use of the bobbin in certain outsole shoe sewing machines such as that of the horn type, it is mounted in the shell 4 of the shuttle. In order to prevent loosening or breaking down of the bobbin, causing snarling in the shuttle as the thread is pulled or unwound from the inside of 2 the bobbin, the bobbin must tightly fit the cylindrical wall of the shell.

In accordance with the present invention, my improved bobbin in its preferred form is provided with a plurality of serrations or protuberances 6 which extend transversely of the peripheral surface of the bobbins and are spaced apart, and taper from the outer toward the inner side of the bobbin.

The protuberances 6 may be for-med during the compression of the bobbins circumierentially and axially. The device illustrated in Fig. 4 may be employed for thus compressing the bobbins and forming the protuberances 6. This device comprises a support member [0 on which the bobbin to be compressed is placed, the bobbin being held centered by means of a pin l2 received in the center of the bobbin. A plunger I4 is mounted to move vertically toward and from the support H) so that when a bobbin is in position and the plunger is moved downwardly, the bobbin is compressed axially between the end of the plunger l4 and the support ID. The bobbin may be compressed circumferentially by means of a split collar I6 which surrounds the bobbin when on the support Ill. The segments of the collar I6 are moved inwardly to compress the bobbin circumferentially by any suitable means. As shown the outer sides of the segments of the collar are inclined upwardly and outwardly and engage a correspondingly inclined surface l8 on a stationary head or block 20. When the segments of the collar l6 are retracted they. assume the dotted position shown in Fig. 5, and when the plunger l4 moves downwardly to compress the bobbin axially, the lower end thereof engages the tops of the collar segments and forces the segments downwardly. Owing to the inclined surfaces l8, the segments are forced inwardly to efiect the desired circumferential compression of the bobbin.

In order to provide the protuberances 6, the segments of the collar are provided with suitably formed grooves 22 whereby when the segmental collar is moved to compress the bobbin circumferentially, the protuberances 6 are formed in the periphery of the bobbin. It will be noted that the portions of the bobbin constituting the protuberances '6, are not compressed as much as 7 the remaining portions of the periphery of the be completely inserted in the shell. The wedging action of the yielding protuberances cause them to firmly engage the wall of the shell. If the bobbin is of small diameter, the protuberances tightly grip the shell and keep the bobbin from turning, and if the bobbin is large the protuberances flatten out allowing the bobbin to enter and fit the shell. Thus proper fitting of the bobbins in the shells may be effected irrespective of the bobbins or shells being slightly out-ofround, or slight variations in the diameter of the bobbins.

In the form shown in Fig. 6, in place of the protuberances 6, an annular protuberance 24 is formed on the periphery of the bobbin. In the form shown in Fig. 7 more or less circular protuberances 26 are formed which are arranged in staggered relation. While it is preferred to employ the tapering protuberances 6 shown in Fig. 1, it will be apparent that the modified forms may be employed in certain instances.

As will be evident to those skilled in the art, my invention permits various modifications without departing from the spirit thereof or the scope of the appended claims.

What I claim is:

1. A bobbin for sewing machine shuttles of the class described, comprising thread cross-wound into an annular mass having longitudinally tapering protuberances formed on the periphery thereof, extending transversely of said periphery, and spaced apart circumferentially thereof.

2. A bobbin for sewing machine shuttles of the class described, comprising thread cross-wound into an annular mass having a protuberance extending circumferentially of the periphery thereof and beveled transversely of said periphery.

3. A bobbin for sewing machine shuttles of the class described, comprising thread cross-wound into an annular mass having at least one protuberance formed on the periphery thereof, and beveled transversely of said periphery.

4. A bobbin for sewing machine shuttles of the class described, comprising thread cross-wound into an annular mass having a plurality of protuberances formed on the periphery thereof, spaced apart in staggered relation, and beveled transversely of said periphery.

5. The method of forming a bobbin for sewing machine shuttles of the class described which comprises cross-winding thread into an annular mass, and compressing the mass axially and circumferentially thereof the circumferential pressure applied being interrupted so as to form protuberances at spaced points.

6. A device for operating on bobbins for sewing machine shuttles of the class described comprising a split collar adapted to be contracted to compress the bobbin circumferentially, said collar having transverse grooves in the work-engaging surface thereof so as to cause protuberances to be formed on the periphery of the bobbin during said compressing operation.

JOHN HOWARD ANDERSON.

No references cited.

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